Current touchscreen technology makes for intuitive humancomputer interactions but often lacks haptic feedback offered by conventional input methods. Typing text on a virtual keyboard is arguably the task in which the absence of tactile cues imparts performance and comfort the most. Here we investigated the feasibility of modulating friction via ultrasonic vibration as a function of the pressing force to simulate a tactile feedback similar to a keystroke. Ultrasonic vibration is generally used… CONTINUE READING